1. Technical Field
The present invention relates to package structures of MEMS microphones, and more particularly, to a MEMS microphone package structure having a non-planar substrate, characterized in that the non-planar substrate is reinforced by a sidewall thereof, such that a carrying bottom portion of the non-planar substrate can be thinned.
2. Description of Related Art
Compared to conventional microphones, MEMS microphones are being widely used in the electronic products due to the advantages of being compact, energy-efficient, and cheap. Referring to FIG. 1, a conventional MEMS microphone package structure 70 comprises a substrate 71. A sound wave transducer 72 and an application-specific integrated circuit (ASIC) 73 are electrically connected thereto and disposed/mounted on the substrate 71. The ASIC 73 is electrically connected to external components by a plurality of electrical connection structures 76 on the substrate 71. The substrate 71 is covered by a cap 74 to protect inside components of the MEMS microphone. As shown in FIG. 1, the substrate 71 of the conventional MEMS microphone package structure 70 carries the stress exerted by the back cover 74, the sound wave transducer 72, and the ASIC 73. As considerations are given to structural strength, the thickness of the substrate 71 cannot be thinning, and it is unfavorable to the current trend toward electro-acoustic products. Besides, the thinning of the MEMS microphone package structure 70 will decrease the volume of a back chamber 75 of the MEMS microphone package structure 70. In view of this, a reduction in the thickness of the substrate 71 is to increase the capacity of the back chamber 75, and further enhance the acoustic performance of the MEMS microphone, such as the sensibility, signal-to-noise ratio, and frequency response of the sound perceived.